The beta 1 domain of the mouse E beta chain is important for restricted antigen presentation to helper T-cell hybridomas.

Abstract

A hybrid E.beta. gene was constructed by replacing the 2nd exon of the .**GRAPHIC**. gene (which encodes the majority of the .beta.1 protein domain) with the corresponding exon from the .**GRAPHIC**. gene. The hybrid gene was introduced into a d haplotype host, the lymphoma .beta.-cell line A20-2J, and an E.alpha.E.beta. dimer composed of the endogenous .**GRAPHIC**. chain and the product of the hybrid .**GRAPHIC**. gene was immunoprecipitated from extracts of transfected cells with an .**GRAPHIC**. monoclonal antibody. Transfected cells have acquired the ability to present antigen to .**GRAPHIC**. helper T-cell hybridomas, indicating that the 2nd exon of the gene for the E.beta. chain encodes sequences required for the restricted recognition of the antigen-presenting cell by the class II-restricted responder T-cell.